World population is slowing and then expected to decline.

There's been some hysteria the past several decades that over population was going to destroy planet. Eat up valuable natural resources. Turns out that's not the case. In fact, economic development reduces the birth rate and could result in other problems from a declining population. 

The world’s seemingly relentless march toward overpopulation achieved a notable milestone in 2012: Somewhere on the planet, according to U.S. Census Bureau estimates, the 7 billionth living person came into existence....

A somewhat more arcane milestone, meanwhile, generated no media coverage at all: It took humankind 13 years to add its 7 billionth. That’s longer than the 12 years it took to add the 6 billionth—the first time in human history that interval had grown. (The 2 billionth, 3 billionth, 4 billionth, and 5 billionth took 123, 33, 14, and 13 years, respectively.) In other words, the rate of global population growth has slowed. And it’s expected to keep slowing. Indeed, according to experts’ best estimates, the total population of Earth will stop growing within the lifespan of people alive today.

And then it will fall.

This is a counterintuitive notion in the United States, where we’ve heard often and loudly that world population growth is a perilous and perhaps unavoidable threat to our future as a species. But population decline is a very familiar concept in the rest of the developed world, where fertility has long since fallen far below the 2.1 live births per woman required to maintain population equilibrium. In Germany, the birthrate has sunk to just 1.36, worse even than its low-fertility neighbors Spain (1.48) and Italy (1.4). The way things are going, Western Europe as a whole will most likely shrink from 460 million to just 350 million by the end of the century. That’s not so bad compared with Russia and China, each of whose populations could fall by half. As you may not be surprised to learn, the Germans have coined a polysyllabic word for this quandary: Schrumpf-Gesellschaft, or “shrinking society.”

American media have largely ignored the issue of population decline for the simple reason that it hasn’t happened here yet. Unlike Europe, the United States has long been the beneficiary of robust immigration. This has helped us not only by directly bolstering the number of people calling the United States home but also by propping up the birthrate, since immigrant women tend to produce far more children than the native-born do.

 Developing countries are now experiencing declining birth rates.

Moreover, the poor, highly fertile countries that once churned out immigrants by the boatload are now experiencing birthrate declines of their own. From 1960 to 2009, Mexico’s fertility rate tumbled from 7.3 live births per woman to 2.4, India’s dropped from six to 2.5, and Brazil’s fell from 6.15 to 1.9. Even in sub-Saharan Africa, where the average birthrate remains a relatively blistering 4.66, fertility is projected to fall below replacement level by the 2070s. This change in developing countries will affect not only the U.S. population, of course, but eventually the world’s.

 What's the reason?

“For hundreds of thousands of years,” explains Warren Sanderson, a professor of economics at Stony Brook University, “in order for humanity to survive things like epidemics and wars and famine, birthrates had to be very high.” Eventually, thanks to technology, death rates started to fall in Europe and in North America, and the population size soared. In time, though, birthrates fell as well, and the population leveled out. The same pattern has repeated in countries around the world. Demographic transition, Sanderson says, “is a shift between two very different long-run states: from high death rates and high birthrates to low death rates and low birthrates.” Not only is the pattern well-documented, it’s well under way: Already, more than half the world’s population is reproducing at below the replacement rate.

 Now the opposite specter of disaster from too few births is being raised.

If the Germany of today is the rest of the world tomorrow, then the future is going to look a lot different than we thought. Instead of skyrocketing toward uncountable Malthusian multitudes, researchers at Austria’s International Institute for Applied Systems Analysis foresee the global population maxing out at 9 billion some time around 2070. On the bright side, the long-dreaded resource shortage may turn out not to be a problem at all. On the not-so-bright side, the demographic shift toward more retirees and fewer workers could throw the rest of the world into the kind of interminable economic stagnation that Japan is experiencing right now.

 And in the long term—on the order of centuries—we could be looking at the literal extinction of humanity.

That might sound like an outrageous claim, but it comes down to simple math. According to a 2008 IIASA report, if the world stabilizes at a total fertility rate of 1.5—where Europe is today—then by 2200 the global population will fall to half of what it is today. By 2300, it’ll barely scratch 1 billion. (The authors of the report tell me that in the years since the initial publication, some details have changed—Europe’s population is falling faster than was previously anticipated, while Africa’s birthrate is declining more slowly—but the overall outlook is the same.) Extend the trend line, and within a few dozen generations you’re talking about a global population small enough to fit in a nursing home.

It’s far from certain that any of this will come to pass. IIASA’s numbers are based on probabilistic projections, meaning that demographers try to identify the key factors affecting population growth and then try to assess the likelihood that each will occur. The several layers of guesswork magnify potential errors. “We simply don’t know for sure what will be the population size at a certain time in the future,” demographer Wolfgang Lutz told IIASA conference-goers earlier this year. “There are huge uncertainties involved.” Still, it’s worth discussing, because focusing too single-mindedly on the problem of overpopulation could have disastrous consequences—see China’s one-child policy.

Some countries are now paying people to have kids.

One of the most contentious issues is the question of whether birthrates in developed countries will remain low. The United Nation’s most recent forecast, released in 2010, assumes that low-fertility countries will eventually revert to a birthrate of around 2.0. In that scenario, the world population tops out at about 10 billion and stays there. But there’s no reason to believe that that birthrates will behave in that way—no one has every observed an inherent human tendency to have a nice, arithmetically stable 2.1 children per couple. On the contrary, people either tend to have an enormous number of kids (as they did throughout most of human history and still do in the most impoverished, war-torn parts of Africa) or far too few. We know how to dampen excessive population growth—just educate girls. The other problem has proved much more intractable: No one’s figured out how to boost fertility in countries where it has imploded. Singapore has been encouraging parenthood for nearly 30 years, with cash incentives of up to $18,000 per child. Its birthrate? A gasping-for-air 1.2. When Sweden started offering parents generous support, the birthrate soared but then fell back again, and after years of fluctuating, it now stands at 1.9—very high for Europe but still below replacement level.

And people don't want to have children because of cost and I would say a "self" focus.

The reason for the implacability of demographic transition can be expressed in one word: education. One of the first things that countries do when they start to develop is educate their young people, including girls. That dramatically improves the size and quality of the workforce. But it also introduces an opportunity cost for having babies. “Women with more schooling tend to have fewer children,” says William Butz, a senior research scholar at IIASA.

 In developed countries, childrearing has become a lifestyle option tailored to each couple’s preferences. Maximizing fertility is rarely a priority. My wife and I are a case in point. I’m 46, she’s 39, and we have two toddlers. We waited about as long to have kids as we feasibly could because we were invested in building our careers and, frankly, enjoying all the experiences that those careers let us have. If wanted to pop out another ankle-biter right now, our ageing bodies might just allow us to do so. But we have no intention of trying. As much as we adore our little guys, they’re a lot of work and frighteningly expensive. Most of our friends have just one or two kids, too, and like us they regard the prospect of having three or four kids the way most people look at ultramarathoning or transoceanic sailing—admirable pursuits, but only for the very committed.

It's the children, stupid.

The 1992 Clinton Campaign made famous the phrase, "It's the economy stupid". It was his theme for defeating President George Bush Sr.

I think a modified phrase, "It's the children stupid" applies to an analysis of the future well-being of our society.

I know folks on the left love to trumpet children to expand spending on social programs though many of the initiatives are often anti-children, e.g. pro-abortion policies and funding kill unborn children, birth control advocacy results in fewer children, and gay "marriage" intentionally denies what children need most - both their mom and their dad in their lives.

Ross Douthat conservative columnist with the New York Times has an interesting article on the declining birth rates in the US, "More Babies, Please."

First, the US's birth rate has geopolitical implications.

In the eternally recurring debates about whether some rival great power will knock the United States off its global perch, there has always been one excellent reason to bet on a second American century: We have more babies than the competition.

It’s a near-universal law that modernity reduces fertility. But compared with the swiftly aging nations of East Asia and Western Europe, the American birthrate has proved consistently resilient, hovering around the level required to keep a population stable or growing over the long run.

America’s demographic edge has a variety of sources: our famous religiosity, our vast interior and wide-open spaces (and the four-bedroom detached houses they make possible), our willingness to welcome immigrants (who tend to have higher birthrates than the native-born).

It implicates economic growth.

And it clearly is an edge. Today’s babies are tomorrow’s taxpayers and workers and entrepreneurs, and relatively youthful populations speed economic growth and keep spending commitments affordable. Thanks to our relative demographic dynamism, the America of 50 years hence may not only have more workers per retiree than countries like Japan and Germany, but also have more than emerging powers like China and Brazil.

 But now it's dropping dramatically.

If, that is, our dynamism persists. But that’s no longer a sure thing. American fertility plunged with the stock market in 2008, and it hasn’t recovered. Last week, the Pew Research Center reported that U.S. birthrates hit the lowest rate ever recorded in 2011, with just 63 births per 1,000 women of childbearing age. (The rate was 71 per 1,000 in 1990.) For the first time in recent memory, Americans are having fewer babies than the French or British.

The plunge might be temporary. American fertility plummeted during the Great Depression, and more recent downturns have produced modest dips as well. This time, the birthrate has fallen fastest among foreign-born Americans, and particularly among Hispanics, who saw huge amounts of wealth evaporate with the housing bust. Many people may simply be postponing childbearing until better times return, and a few years of swift growth could produce a miniature baby boom.

 Immigrants won't fill the gap.

But deeper forces than the financial crisis may keep American fertility rates depressed. Foreign-born birthrates will probably gradually recover from their current nadir, but with fertility in decline across Mexico and Latin America, it isn’t clear that the United States can continue to rely heavily on immigrant birthrates to help drive population growth.

Among the native-born working class, meanwhile, there was a retreat from child rearing even before the Great Recession hit. For Americans without college degrees, economic instability and a shortage of marriageable men seem to be furthering two trends in tandem: more women are having children out of wedlock, and fewer are raising families at all.

 Then he discusses why it's happening.

Finally, there’s been a broader cultural shift away from a child-centric understanding of romance and marriage. In 1990, 65 percent of Americans told Pew that children were “very important” to a successful marriage; in 2007, just before the current baby bust, only 41 percent agreed. (That trend goes a long way toward explaining why gay marriage, which formally severs wedlock from sex differences and procreation, has gone from a nonstarter to a no-brainer for so many people.)

 What can be done to change it, by the government?  Some things but the problem goes much deeper.

Government’s power over fertility rates is limited, but not nonexistent. America has no real family policy to speak of at the moment, and the evidence from countries like Sweden and France suggests that reducing the ever-rising cost of having kids can help fertility rates rebound. Whether this means a more family-friendly tax code, a push for more flexible work hours, or an effort to reduce the cost of college, there’s clearly room for creative policy to make some difference.

  Then he points out that low birth rates are a symptom of -- decadence.

More broadly, a more secure economic foundation beneath working-class Americans would presumably help promote childbearing as well. Stable families are crucial to prosperity and mobility, but the reverse is also true, and policies that made it easier to climb the economic ladder would make it easier to raise a family as well.

Beneath these policy debates, though, lie cultural forces that no legislator can really hope to change. The retreat from child rearing is, at some level, a symptom of late-modern exhaustion — a decadence that first arose in the West but now haunts rich societies around the globe. It’s a spirit that privileges the present over the future, chooses stagnation over innovation, prefers what already exists over what might be. It embraces the comforts and pleasures of modernity, while shrugging off the basic sacrifices that built our civilization in the first place.

Such decadence need not be permanent, but neither can it be undone by political willpower alone. It can only be reversed by the slow accumulation of individual choices, which is how all social and cultural recoveries are ultimately made. 

 Strong words but it's important we face these developments square on.

Looming social crises - 40 percent of kids born out of wedlock and record low birth rates.

A recent story noted a CDC report showing record low birth rates and extremely high out of wedlock birth percentages.

The birth rate in the United States hit an all-time low in 2011, according to a report released this month by the federal Centers for Disease Control and Prevention.

“The 2011 preliminary number of U.S. births was 3,953,593, 1 percent less (or 45,793 fewer) births than in 2010; the general fertility rate (63.3 per 1,000 women age 15-44 years) declined to the lowest rate ever reported for the United States,” said the report.

More than 40 percent of all babies born in the country last year, the report said, were born to unmarried women....

The percentage of American-born babies who were delivered by unmarried women actually declined slightly from 40.8 percent in 2010 to 40.7 percent in 2011.

In 2011, 1,606,087 babies were born to unmarried women and 2,347,506 were born to married women.

Although the percentage of babies born to unmarried women was highest among teens, the percentage of babies delivered by unmarried women of older ages increased from 2010 to 2011.

In 2010, 33.9 percent of the babies delivered by women 25-29 were delivered by unmarried women, and in 2011 that increased to 34.4 percent. In 2010, 21.1 percent of babies delivered by women 30-34 were delivered by unmarried women, and in 2011 that increased to 21.6 percent. In 2010, 19.6 percent of babies delivered by women 35-39 were delivered by unmarried mothers and in 2011 that increased to 21.1 percent. In 2010, 21.7 percent of babies delivered by women 40 and over were delivered by unmarried mothers and in 2011 that increased to 22.4 percent.

For many, it's no big deal.  But a closer look reveals it is a big deal.

Declining birth rates means a smaller population which will impact economic growth and the ability of government to sustain it's current expenditures.  This will impact social programs and everything else government does.  It also will also increase pressure for higher taxes.

Higher out of wedlock birth rates means a significant, negative impact on character formation in the next generation.  Lack of fathers means kids are more likely to engage in criminal activity, do poorly in school, and a host of social of other social pathologies.

I compare it to the effect termites have on a house.  It destroys the foundation out sight, until one day the house collapses.  Same with the breakdown of marriage and child rearing.  If we do nothing, society will break down and collapses.

Same sex "marriage" is relevant to this discussion. Redefining marriage means mothers and fathers are no longer important.  Fathers become superfluous.  The state, if a new, genderless definition is adopted, will no longer be in a position of encouraging the involvement of fathers in children's lives because this would be discriminatory against same sex, female households.